Method of making annular members



' NbvQ24, 1931; F. A. HAUGHTON METHOD OF MAKING ANNULAR MEMBERSFi-led'Oct. 31, 1928 4 Figl.

by r A Has Attorney bending.

Patented Nov. 24,1931

UNITED STATES PATENT OFFICE FRANK A. HAUGH'ION', O1 SCHENECTADY, NEWYORK, ABSIGNOB 1'0 GENERAL-EEG I i TBIC COMPANY, ACORPORATION 0FNEW-YORK name!) 01' mxme muumm armaments:

Application filed October 31 1928. Serial No. 316,280.

My invention relates to a method of making annular members by rollingslabs or plates of material into annular form, which are of generalutility, but are particularly useful in making dynamo-electric machineframes and cylindrical pressure vessels.

- It has been the ractice heretof re in making annular mem are out ofslabs or plates of steel to form them in bending rolls. These rollsconsist of two stationary rolls arranged side by side and spacedapart-and a vertically adjustable roll usually arranged directly abovethe space between the stationary rolls.

Ordinarily the slab or plate of material has been first formed, adjacentthe ends, of the curvature required in the completed. annular memberbecause these portions could not be formed with this curvature by meansof the rolls. This isdue to the fact that in rolling the slab themaximum bending stress therein is approximately midway between thestationary rolls and decreases in direct proportion to thedistancetoward the end thereof, so that when the portion adjacent the end of,the slab is just enterin or just leaving the rolls, bending therein taes place almost entirely at a point spaced from the end thereof adistance approximately equal to half of the spacing of the stationaryrolls, and practically not at all between this point and the end of theslab. In the case of, thick slabs or plates the portions adjacent theends have, therefore, been formed in a suitable press, and if they werebeing worked hot it was necessary to reheat them after the formingoperation before they could be rolled into annular form. In the case ofthin slabs or plates it has been the practice to form the portionsadjacent the ends of the desired I curvature by placing the slabs orplates in the rolls with the end portion projecting a small amountbeyond one of the lower rolls and bend the same downwardly as desired bymeans of a sledge hammer. This necessitated removing the slab or. platefrom the rolls and turning the same over, as

the 'rol s bend the ends of the slab or plate upwardly during therolling operation.

The object of my invention is to carry out a method of making an annularmember such tant when hot slabs are that the slab or plate can be rolledinto annu lar form entirely by the use of the rolls and without anyinterruption in the process of manufacture. This is imporp'articularlinto aneing r01 nular form as the interruption caused b the independentpreliminary operation of orming the ends, necessitates reheating of theslab or plate, in many cases,.before the rolling operation can becontinued. I carry out this method by forming the portions adjacent theends of-the slab or plate of varying cross-section such that they can begiven uniform curvature in the bending rolls, and then roll the slab orplate into annular form with the ends engaging each other.-

My invention will be more fully set forth in the following descriptionreferring tothe accompanying drawings, and the features of novelty whichcharacterize my invention will be pointed out with particularity in theclaims annexed to and forming a part of this specification.

In the drawings Fig. 1 is a plan view of a slab having the ends formedinaccordance with my invention; Fig. 2 is a diagrammatic view of thebendingrolls showing the end of the slab arranged therein; Fig. 3 is aview similar to'Fig.2 showing the rolls adjusted to bend the slab; Fig.4 is a perspective View of the completed annular member, and Flg. 5 isaperspective view of a plate rolled into annular form in accordance'withmy invent-ion, such as would be us ful in making a container or pressurevessel. 1

Referring to the drawings, the rolls which I employ in forming slabs orplates into annular members are commonly known as pyramid rolls andcomprise two rolls 10 and 10a which are arranged side by side andsupported in fixed relation to each other, and a vertically adjustableroll 11 which is arran ed directly above the space between thestationary rolls. In carryin out 111 method of making an annular 'memer, I rst form the ends of the slab 12 so that they can be bentwithuniform curvature in the bending rolls without twisting the ends of theslab. I obtain uniform curvature of the port bn adjacent the ends of the.slab by forming them of a cross-sectional area which varies from theends to a point spaced from the ends thereof a distance approximatelywhich distance is half the distance 1) between the rolls as shownin-Fig. 2. By

this construction when the slab is placed in the upper roll is adjustedas shown in Fig;

the rolls with one extremity .15 above the center of'the bottom roll 10as in Fig. 2 and 3 to bend the slab 12,'the maximum bending momentexerted upon the slab will be directly under the 'axis -of the upperroll 11 and decrease in proportion in both directions along the slab asthe points ofcontact with the two lower rolls is approached. -Owing,however,

a to the width of the slab being reduced in m between the said point ofmaximumbending.

proportion as the end is approached commencing from the point of maximumbending moment, any cross section of the slab throughout this'portionisequally stressed by downward adjustment of the upper roll 11''andconsequently will bend equally throughout this ortion. Coincidentwith the downward a justment of the 11 per roll 11 practicallyno bendingwill ta e place moment and the point ofcontact with the lower roll 10afor the reason that the slab is of constant width throughout thisportion and consequently the stress in any cross sec ends thereof. are.

tion of thisportion becomes less in proportion as the point of. contactwith roll 10a is a proached.

- In. ordergto' preyent twisting of slab 12, whenthe portion adjacentthe end thereof passes into out -of the rolls, .1 vary thecross-sectional area in such manner'that the mmetri'cal with respect totheloiifitudina axis of the slab. As shown in Fig. 1, -I do this byforming a -V t-hereo. tion 15,

sha d' notch 18 in one end so as to rovide pro ections 14'on" both'sides of the s ab, app 'x v y same distance from the axis of theslab, so

- that they they will balance each 'other and there will be no tendencyto twist these por-f tions when they pass into and out of the rolls. L

Moreover, there is no tendency for the. V-

' beent the joint when the cylindrical vessel was subat the resultant ofthe forces actingon each of the portions'is the shaped portion 15 of theslab. to twist when it passes into and out of the rolls, as theresultant of the forces exerted thereon by the rolls is on thelongitudinal axis of theslab.

After forming the endsof the slab 12 in this manner, I place oneendthereof between the rolls 10, 10a and 11, as shown in Fig. 2, andlower roll 11 to bend the slab as shown in Fig. 3. .I their cause therolls to be rotated in the direction indicated by the arrows in- .Fig. 3and bend the slab throughout its length to the curvature correspondingto the amount of adjustment of the u per roll '11. When the other end ofthe sla by reason of rotating the rolls, has reached the point ofcontact with roll 10a I make a further downward adjustment of then perroll 11 causing the portion of the slab romthe point of maximum bendingmoment tothis end to bend uniformly throughout due to itsuniformly-decreasing efi'ective width at the portions'14, Figs. 1 and 4.I then rotate the rolls in the opposite direction and im art afurtherdegree of'curvature to the-s ab. I repeat this cycle'as often asnecessary until the slab is formed into a complete circle and the end 15conforms to the notch-.13, and I then revolve the annular memberin therolls severalv times with only a very. slight downward ad'ustment of theroll ll thereby obtaining a igh' degree of accuracy in true circularform and causing the portion 15 to be firmlyseated in the notch. 13.IIcan do this without interruption on account of the overlapp'i I thenremove'the annular member from the rolls, which is now in theform'shown-in Fig.-

4 and weld the portion 15 to the portions 14.

' In making cylindrical containers or pressure vessels'one of theobjections to the use of longitudinally extending welded joint has efrequent localization vof stresses at jected to pressure. This has beendue to the fact that the side walls of the vessels have not 7 been oftrue circular form, so that when pressure has beenapplied thereto theside walls tended to assume true circular form which subjected thejoints to a combifiedlbending and tension stress. and often caused themto fail. In accordance-with my method this ob- --jection to a weldedjoint in a vessel of this kind has been overcome by making the joint ofsuch form that localization of stresses can occur only over a small Irtion of the joint,

and rollin a plate constituting the'cylindri-' cal wall o the vesselinto true circular formso that the wall is subjected-only to tensionstress. I do this by rolling a plate into true circular form in bendingro ls of the arrangement diagrammatically shown in Fig. 2, and

forming the jointof interfitting portions so thatthe welded portion of alon itudinal sect on 0f the joint includes a sma proportion ends whichavoids an abru t open gap at t e ends into which each of t e rollswould. jolt in passing;

no I

thereof. Forming the joint of interfitting portions also enables me toroll the plate into annular form with uniform curvature throughout itslength entirely by. the use of bending rolls, as the portions adjacentthe V ends are formed of varying cross-section such curvature as thatthe rolls give them the same This method the main portion of the plate.

. is carried out in the present instance by first 1 be given thecurvature forming one end of a plate 16 with a plurality of notches of adepth approximately length, and adapted to conform to the notches in thecompleted annular member. In this way the portlons adj aceut the ends ofthe plate vary in cross-section so that they can desired in the bendingrolls without removing the plate from the rolls during the process ofmanufacture, and without twisting the ends of the plate. By forming theprojections 18 and notches 17 in the ends of the plate in this way, itWlll be seenthat I obtain greater strength of the joint connecting themtogether, which is welded in the completed annular member,

than in a construction in which two straight abutting edgesare weldedtogether in accordance with the usual practice, because of the greaterlength of the weld and the-small proportion of the weld in anylongitudinal section of the 'oint. After forming the notches, and proections in the ends of the plate I roll the same into annular form shownin Fig. 5, in

is'rolled in annular form as above described, and the ends thereof arewelded together.

Modifications of the particular method which I have disclosed will occurto those skilled in the art, so that I do not'desire my invention to belimited to the method set forth, except as defined in the appendedclaims.

What I claim as new and desire to secure by Letters Patent of the UnitedStates. is:

1. The method of making-an annular member comprisingforming a portionadjacent each of the ends of a slab of material formly varyingcross-section throughout their length so that they can be given uniformcurvature in bending rolls, and rolling the slab in a direction from oneof the formed ends thereof toward the other into annular form with theends engaging each other.

2. The method of making an annular member comprising making a' portionadjacent one end of a slab of varying cross-section throughout theirlength the same mannerthat the slab 12 of unimaterial of uniformly byforming a V-s'hapednotch which is substantially symmetrical with respectto thelongitudinal axis ofthe slab' and the other end with a V- hapedportion uniformly varying in cross-section throughout its length andsubstantially symmetrical with respect to the longitudinal axis of theslab which is adapted to conform to the notch, and rolling the slab. ina direction from one of the formed ends thereof toward the other intoannular form with the portion conforming to the notch.

' 3. The method of making an annular men ber comprising making a ortionadjacent one end of a slab of material of uniforml varying cross-sectionthroughout its length by forming a notch which is substantiallysymmetrical with res ct to the longitudinal axis ofthe slab an I theother end with a portion of uniformly'varying cross-section throughoutits length" and substantially symmetrical with of theislab wh is adaptedto conform to the notch, rolling the-slab in' adirection from formedends thereof toward the one of the 7 other into annular form; with theportion" conforming to the notch,and securingthe ends ofthe slabtogether.

.4. The method of making an annular member comprising making a rtionadjacent one end of a slab of material of uniformly varyingcross-section throughout its len by forming a V-shaped notch which is.substantially s mmetrical with respect to the longitudina axis of the.slab and the other end'with a V-shap va'ryin cross-section throughoutits len and su stantially symmetrical with we to the longitudinal axisof the slab whi'c is adapted to conform to the notch, rolling the slabin-a direction from one of the formed ends thereof toward the other intoannular form ,with the ortion conforming to the notlclh,.and'secur1ngthe ends of the slab tot er. 5. The method of making an annular membercomprising making a ortion adjacent one end of a slab of materlal ofuniforml varying cross-section throughout its lengt by forming aV-shaped notch which is substantially symmetrical with respect to thelongitudinal axis of the slab and the'other endwitha V-sha d portionofuniformlyJ varying cross sect1on throughout its lengt substantiallysymmetrical with respect to the i v. In

thereof toward the ther into annular form with the portion conforming tothe notch, and welding the ends of the slab together.

6. The method'of making an annular member which comprises forming oneend slab of material with a V-shap'ed'notch of'a depth equal to half thedistance between the axes of relatively fixed bending rolls and edportion of uniformlyrespect to the longitudinal axis 7 I substantial]symmetrical with respect to the A longitndina axis oi the slab formin'the other end of the slab with a il sha. por-: tion of glen equal-tohalf the distance between the re tively fixed rolls and substantiallysymmetrical with respect to the longitutlinll axis of the slab which isadapted to conformto the notch, and rolling the slab into annular formwith the portion conformtothe notch.

witness whereof, I have hereunto set my hand'this 30th da of October,1928. FR N-K A. HAUGHTON.

